Regulation plate, plating apparatus equipped with the same, and plating method

ABSTRACT

The present invention provides a regulation plate and a plating apparatus equipped with the regulation plate which can curb reduction in in-plane uniformity due to influence of a terminal effect with respect to plural substrates differing in characteristics and processing conditions. One form of the present invention provides a regulation plate used to adjust an electric current between an anode and a substrate to be plated. The regulation plate includes a plate main body provided with an opening adapted to allow passage of an electric current; plural first blades used to narrow a diameter of the opening; and a first moving mechanism adapted to translate the plural first blades in a radial direction of the opening.

TECHNICAL FIELD

The present invention relates to a regulation plate, a plating apparatus equipped with the regulation plate, and a plating method.

BACKGROUND ART

Conventionally, wiring is formed in minute wiring grooves, holes, or resist openings provided on surfaces of substrates such as semiconductor wafers or bumps (bumpy electrodes) used to electrically connect to electrodes of a package which are formed on the surfaces of the substrates. As a method for forming the wiring and bumps, an electrolytic plating process, vacuum deposition process, printing process, ball bumping process, and the like are known, for example. With increases in I/O counts and pitch refinement on semiconductor chips, the electrolytic plating process which allows refinement and shows comparatively stable performance has come to be used frequently.

When wiring or bumps are formed by the electrolytic plating process, a seed layer (feeder layer) with low electrical resistance is formed on surfaces of barrier metal provided in the wiring grooves, holes, or resist openings in the substrates. A plating film grows on a surface of the seed layer. In recent years, seed layers with thinner film thickness have come to be used along with refinement of wiring and bumps. With decreases in the film thickness of the seed layer, the electrical resistance (sheet resistance) of the seed layer increases.

Generally, a substrate to be plated has an electrical contact on its periphery. Consequently, an electric current corresponding to combined resistance of an electrical resistance value of the plating solution and electrical resistance value of the seed layer between a central portion of the substrate and the electrical contact flows through the central portion of the substrate. On the other hand, an electric current almost corresponding to the electrical resistance value of the plating solution flows through the periphery (near the electrical contact) of the substrate. That is, the flow of the electric current to the central portion of the substrate is resisted to an extent corresponding to the electrical resistance value of the seed layer between the central portion of the substrate and the electrical contact. The phenomenon in which electric current concentrates on the periphery of a substrate is referred to as a terminal effect.

In the case of a substrate which has a seed layer comparatively thin in film thickness, the electrical resistance value of the seed layer between the central portion of the substrate and the electrical contact is comparatively high. Therefore, in plating a substrate whose seed layer is comparatively thin in film thickness, the terminal effect is prominent. Consequently, the plating rate in the central portion of the substrate falls, making the plating film in the central portion of the substrate thinner in film thickness than the plating film in the periphery of the substrate and resulting in reduced in-plane uniformity of film thickness.

In order to curb the reduction in the in-plane uniformity of film thickness due to the terminal effect, it is necessary to adjust an electric field applied to the substrate. For example, a plating apparatus is known, in which a regulation plate is installed between an anode and substrate to regulate a potential distribution between the anode and substrate (see PTL 1).

CITATION LIST Patent Literature

PTL 1: Japanese Patent Laid-Open No. 2005-029863

SUMMARY OF INVENTION Technical Problem

Now, the influence of the terminal effect varies with the degree of film thickness of the seed layer on the substrate. Specifically, as described above, when the seed layer is comparatively thin in film thickness, since the sheet resistance is comparatively high, the influence of the terminal effect appears prominently. On the other hand, when the seed layer is comparatively thick in film thickness, since the sheet resistance is comparatively low, the influence of the terminal effect is comparatively small.

Also, the influence of the terminal effect can vary not only with the degree of film thickness of the seed layer, but also with the other factors. For example, when a resist aperture ratio of the substrate is comparatively high, the plating film formed on the substrate has a comparatively large area, where the resist aperture ratio is the area ratio of a portion not covered with resist (open portion of the resist) to a region bordered by an outer edge of the resist. Therefore, as the plating film is formed on the substrate, the formed plating film causes electric current to flow readily in the central portion of the substrate as well. In other words, as the plating film is formed on the substrate, the electrical resistance value between the central portion of the substrate and the electrical contact decreases, gradually reducing the influence of the terminal effect. On the other hand, when the resist aperture ratio of the substrate is comparatively low, the area of the plating film formed on the substrate is relatively small. Consequently, when the resist aperture ratio of the substrate is comparatively low, even if a plating film is formed on the substrate, variation in the electrical resistance value between the central portion of the substrate and the electrical contact is smaller than when the resist aperture ratio of the substrate is comparatively high, and thus the influence of the terminal effect remains large.

Also, when the electrical resistance value of a plating solution used to process the substrate is comparatively high, the influence of the terminal effect is smaller than when the electrical resistance value of the plating solution used to process the substrate is comparatively low. Specifically, if the electrical resistance value of the plating solution is R1 and the electrical resistance value of the seed layer between the central portion of the substrate and the electrical contact is R2, an electric current corresponding to combined resistance value (R1 +R2) flows through the central portion of the substrate. On the other hand, an electric current almost corresponding to the electrical resistance value R1 of the plating solution flows through the periphery (near the electrical contact) of the substrate. Thus, as the electrical resistance value R1 increases, the influence of the electrical resistance value R2 to the electric current flowing through the central portion of the substrate decreases, reducing the influence of the terminal effect.

In this way, the influence of the terminal effect varies with characteristics of the substrate, conditions for processing the substrate, and the like. Therefore, when plural substrates differing in the influence of the terminal effect are plated one after another using a single plating apparatus, in order to curb the reduction in the in-plane uniformity of film thickness due to the terminal effect, it is necessary to adjust the electric fields applied to the substrates, according to the characteristics of the respective substrates, conditions for processing the substrates, and the like. However, in order to adjust the electric fields according to the characteristics of the substrates, conditions for processing the substrates, and the like using a regulation plate such as described in PTL 1, it is necessary to prepare plural regulation plates which suit the characteristics of the substrates, conditions for processing the substrates, and the like.

Besides, even if plural regulation plates are prepared, each time substrates differing in characteristics and processing conditions are processed, it is necessary to take the regulation plate out of the plating bath and install another regulation plate, involving time and effort.

The present invention has been made in view of the above problems and has an object to provide a regulation plate, a plating apparatus equipped with the regulation plate, and a plating method which can curb reduction in in-plane uniformity due to influence of a terminal effect in plating plural substrates differing in characteristics and processing conditions.

Solution to Problem

A first form provides a regulation plate used to adjust an electric current between an anode and a substrate to be plated. The regulation plate comprises: a plate main body provided with a rim forming a first opening adapted to allow passage of an electric current; plural first blades used to narrow a diameter of the first opening; and a first moving mechanism adapted to translate the plural first blades in a radial direction of the first opening.

The first form allows the diameter of the opening to be adjusted by narrowing a diameter of an opening in the regulation plate using the first blades. This makes it possible to curb reduction in in-plane uniformity due to influence of a terminal effect when a first substrate and second substrate differ from each other in characteristics or processing conditions. Specifically, in plating the substrate under conditions in which the influence of the terminal effect appears prominently, by reducing the diameter of the opening in the regulation plate, the film deposition rate on the periphery of the substrate can be slowed down, making it possible to improve the in-plane uniformity on the substrate. Also, since the first blades are configured to perform translational movement, the plural first blades can move in the radial direction while maintaining an angular relationship among the first blades. Therefore, a perfectly circular shape of the opening formed by the first blades can be maintained better than when plural aperture blades rotate around a predetermined axis, reducing the diameter of the opening as with an aperture mechanism of a camera.

According to a second form, in the first form, the first moving mechanism includes a ring member placed along the rim; either of the ring member and the plural first blades includes a slide slot inclined in the radial direction of the first opening; and another of the ring member and the plural first blades includes a slide pin adapted to slide along the slide slot.

According to the second form, the slide pin provided on the other of the ring member and the plural first blades slide along the slide slot provided in either of the ring member and the plural first blades. Therefore, as the ring member is rotated in a circumferential direction, the slide pin slide along the slide slot, allowing the first blades to move in the radial direction of the first opening.

According to a third form, in the second form, the first moving mechanism includes a blade presser member fixed on a side opposite the ring member of the plural first blades; either of the blade presser member and the plural first blades includes a guide slot formed in parallel to a translation direction of the first blades; and another of the blade presser member and the plural first blades includes a guide pin adapted to slide along the guide slot.

According to the second form, the guide pins provided in the other of the blade presser member and the plural first blades slide along the guide slots provided in either of the blade presser member and the plural first blades. Therefore, when the plural first blades is moved by the moving mechanism, the first blades can be translated in a desired direction while preventing the plural first blades from performing rotary motion.

According to a fourth form, in the second or third form, the first moving mechanism includes a rotating member used to rotate the ring member in a circumferential direction; and the rotating member includes a ring portion fixed to the ring member, and a lever portion adapted to rotate the ring portion in the circumferential direction.

According to the fourth form, as the lever portion is operated by an actuator or by hand, the ring portion can be rotated in the circumferential direction. Since the ring portion is fixed to the ring member, the ring member rotates along with rotation of the ring portion. Consequently, the slide slots or slide pins provided in/on the ring member slide with respect to the slide pins or slide slots provided on/in the plural first blades, making it possible to translate the plural first blades.

According to a fifth form, in the fourth form, either of the plate main body and the ring member includes a support slot formed along a rotation direction of the ring member; and another of the plate main body and the ring member includes a support pin slidably engaged with the support slot.

According to the fifth form, the support pin provided on the other of the plate main body and the ring member is slidably engaged with the support slot provided in either of the plate main body and the ring member. As the support pin gets engaged with the support slot, the ring member is supported by the plate main body. Since the support slot is formed along the rotation direction of the ring member, the ring member can be rotated when the support pin slides along the support slot.

According to a sixth form, in any one of the first to fifth forms, an inner peripheral edge of each of the plural first blades is formed into an arc shape and is overlapped with other first blades, forming a substantially circular inner peripheral edge.

According to the sixth form, when the plural first blades perform translational movement in the radial direction of the first opening, reducing the diameter of the opening, the inner peripheral edges of the plural first blades can maintain a substantially circular shape.

According to a seventh form, in any one of the first to sixth forms, the regulation plate further comprises: plural second blades placed at a position shifted from the plural first blades in a direction orthogonal to the radial direction of the first opening and used to narrow the diameter of the first opening; and a second moving mechanism adapted to translate the plural second blades in the radial direction of the first opening.

According to the seventh form, the regulation plate includes formed by the plural first blades and an opening having a second diameter formed by the plural second blades. By appropriately adjusting sizes of the first diameter and second diameter, it is possible to more appropriately adjust the electric current passing through the opening in the regulation plate.

According to an eighth form, in the seventh form, the plural first blades and the plural second blades are arranged such that a straight line joining a center of an opening formed by the first blades and a center of an opening formed by the second blades is orthogonal to the radial direction of the openings.

According to the eighth form, the first blades and the second blades are arranged such that the center of the opening formed by the first blades and the center of the opening formed by the second blades will coincide each other. Therefore, when positioning the regulation plate in a plating bath, there is no need to position the center of the opening formed by the plural first blades and the center of the opening formed by the plural second blades separately. Consequently, even when high accuracy is required of the center position of the opening in the regulation plate, the regulation plate can be positioned easily.

A ninth form provides a regulation plate used to adjust an electric current between an anode and a substrate to be plated. The regulation plate comprises: a first plate main body provided with a first rim forming a first opening adapted to allow passage of an electric current and plural first blades used to narrow a diameter of the first opening; and a second plate main body provided with a second rim forming a second opening adapted to allow passage of an electric current and plural second blades used to narrow a diameter of the second opening. The first plate main body and the second plate main body are coupled together such that a straight line joining a center of an opening formed by the plural first blades and a center of an opening formed by the plural second blades is orthogonal to the radial direction of the openings.

According to the ninth form, the regulation plate includes the opening having a first diameter formed by the plural first blades and the opening having a second diameter formed by the plural second blades. By appropriately adjusting sizes of the first diameter and second diameter, it is possible to more appropriately adjust the electric current passing through the opening in the regulation plate. Also, the first blades and the second blades are arranged such that the center of the opening formed by the first blades and the center of the opening formed by the second blades will coincide each other. Therefore, when positioning the regulation plate in a plating bath, there is no need to position the center of the opening formed by the plural first blades and the center of the opening formed by the plural second blades separately. Consequently, even when high accuracy is required of the center position of the opening in the regulation plate, the regulation plate can be positioned easily.

According to a tenth form, in any one of the seventh to ninth forms, the diameter of the opening formed by the plural first blades and the diameter of the opening formed by the plural second blades are configured to be adjustable independently of each other.

According to the tenth form, the diameter of the opening defined by the plural first blades and the diameter of the opening defined by the plural second blades can be made different from each other. This makes it possible to decrease the diameters of the openings in stages according to the characteristics or processing conditions of the substrate, such as reducing the diameter of the opening defined by the blades closer to the substrate and increasing the diameter of the opening defined by the blades farther from the substrate.

An eleventh form provides a plating apparatus. The plating apparatus comprises: an anode holder configured to hold an anode; a substrate holder placed opposite the anode holder and configured to hold a substrate; an anode mask mounted integrally on the anode holder and provided with a second opening adapted to allow passage of an electric current flowing between the anode and the substrate; and any of the regulation plates described above, wherein the anode mask includes an adjustment mechanism adapted to adjust a diameter of the second opening.

According to the eleventh form, the diameter of the second opening of the anode mask can be adjusted for each of a first substrate and second substrate. This makes it possible to curb reduction in in-plane uniformity due to influence of a terminal effect when the first substrate and second substrate differ from each other in characteristics or processing conditions. Specifically, when the second substrate is plated under conditions in which the influence of the terminal effect appears prominently, by reducing the diameter of the second opening, it is possible to concentrate an electric field on a central portion of the substrate and thereby increase film thickness in the central portion of the substrate. Also, if the diameter of the first opening in the regulation plate is reduced, the film deposition rate on the periphery of the substrate can be slowed down. Thus, if both the diameter of the first opening in the regulation plate and the diameter of the second opening of the anode mask are adjusted, the in-plane uniformity on the substrate W can be further improved.

A twelfth form provides a plating method. The plating method comprises: placing an anode holder in a plating bath, where the anode holder is integrally provided with an anode mask having a first opening adapted to allow passage of an electric current flowing between an anode and a substrate; placing a substrate holder adapted to hold a first substrate in the plating bath; placing a regulation plate between the anode mask and the substrate, where the regulation plate includes a second opening and third opening adapted to allow passage of the electric current flowing between the anode and the substrate; plating the first substrate by adjusting a diameter of the first opening to a first diameter; placing a substrate holder adapted to hold a second substrate in the plating bath; and plating the second substrate by adjusting a diameter of the first opening to a second diameter smaller than the first diameter and by changing the diameters of the second opening and third opening in the regulation plate.

According to the twelfth form, the diameter of the first opening in the anode mask can be adjusted for each of the first substrate and second substrate. This makes it possible to curb reduction in in-plane uniformity due to influence of a terminal effect when the first substrate and second substrate differ from each other in characteristics or processing conditions. Specifically, when the second substrate is plated under conditions in which the influence of the terminal effect appears prominently, by reducing the diameter of the first opening, it is possible to concentrate an electric field on a central portion of the substrate and thereby increase film thickness in the central portion of the substrate. Also, by changing the diameters of the second opening and third opening in the regulation plate, the film deposition rate on the periphery of the substrate can be slowed down, making it possible to improve the in-plane uniformity on the substrate W.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic sectional side view of a plating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic front view of an anode mask.

FIG. 3 is a schematic front view of the anode mask.

FIG. 4 is a perspective front view of a regulation plate, of which a diameter of an opening is comparatively large.

FIG. 5 is a perspective rear view of the regulation plate, of which the diameter of the opening is comparatively large.

FIG. 6 is a front perspective view of the regulation plate, of which the diameter of the opening is comparatively small.

FIG. 7 is an exploded perspective view of the regulation plate.

FIG. 8 is a perspective front view of a plate main body.

FIG. 9 is a perspective rear view of the plate main body.

FIG. 10 is a perspective front view of a ring member.

FIG. 11 shows a perspective front view of a rotating member.

FIG. 12 shows a perspective front view of a first blade making up a blade body.

FIG. 13 is a perspective front view of a blade presser member.

FIG. 14 is a perspective front view of a protective member.

FIG. 15 is a partial front view of the regulation plate as viewed from a front side.

FIG. 16 is a rear view of the regulation plate when an inside diameter of the opening is at the maximum.

FIG. 17 is a rear view of the regulation plate when the inside diameter of the opening is at the minimum.

FIG. 18 is a perspective front view of a regulation plate having plural first blades and plural second blades according to another embodiment.

FIG. 19 is a perspective rear view of the regulation plate having the plural first blades and plural second blades according to the other embodiment.

FIG. 20 is an exploded perspective view of a first plate main body and second plate main body of the regulation plate according to the other embodiment.

FIG. 21 is an exploded perspective view of a first plate main body of the regulation plate according to the other embodiment.

FIG. 22 is an exploded perspective view of a second plate main body of the regulation plate according to the other embodiment.

FIG. 23 is a diagram showing profiles of plating films for substrates with a high resist aperture ratio and substrates with a low resist aperture ratio.

FIG. 24 is a diagram showing profiles of plating films for substrates with a thick seed layer and substrates with a thin seed layer.

FIG. 25 is a diagram showing profiles of plating films on substrates plated in a plating solution having a comparatively high electrical resistance and substrates plated in a plating solution having a comparatively low electrical resistance.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described below with reference to the drawings. In the drawings described below, same or equivalent components are denoted by the same reference numerals, and redundant description thereof will be omitted.

FIG. 1 is a schematic sectional side view of a plating apparatus according to an embodiment of the present invention. As illustrated in FIG. 1, the plating apparatus 10 according to the present embodiment includes an anode holder 20 configured to hold an anode 21, a substrate holder 40 configured to hold a substrate W, and a plating bath 50 adapted to hold the anode holder 20 and substrate holder 40 therein.

As shown in FIG. 1, the plating bath 50 includes a plating treatment bath 52 adapted to hold a plating solution Q containing additives, a plating solution discharge bath 54 adapted to receive and discharge the plating solution Q overflowing from the plating treatment bath 52, and a partition wall 55 adapted to separate the plating treatment bath 52 and plating solution discharge bath 54.

The anode holder 20 holding the anode 21 and substrate holder 40 holding the substrate W are immersed in the plating solution Q in the plating treatment bath 52 and installed there facing each other such that the anode 21 and a surface-to-be-plated W1 of the substrate W will be substantially parallel to each other. A voltage is applied by a plating power supply 59 to the anode 21 and substrate W immersed in the plating solution Q in the plating treatment bath 52. Consequently, the metal ions are reduced on the surface-to-be-plated W1 of the substrate W, forming a film on the surface-to-be-plated W1.

The plating treatment bath 52 has a plating solution supply port 56 for use to supply the plating solution Q into the bath. The plating solution discharge bath 54 has a plating solution discharge port 57 for use to discharge the plating solution Q overflowing from the plating treatment bath 52. The plating solution supply port 56 is located at a bottom of the plating treatment bath 52 while the plating solution discharge port 57 is located at a bottom of the plating solution discharge bath 54.

When supplied to the plating treatment bath 52 through the plating solution supply port 56, the plating solution Q overflows from the plating treatment bath 52, gets over the partition wall 55, and flows into the plating solution discharge bath 54. After flowing into the plating solution discharge bath 54, the plating solution Q is discharged through the plating solution discharge port 57, and impurities are removed by a filter and the like of a plating solution circulation unit 58. The plating solution Q with the impurities removed therefrom is supplied to the plating treatment bath 52 through the plating solution supply port 56 by the plating solution circulation unit 58.

The anode holder 20 includes an anode mask 25 adapted to adjust an electric field between the anode 21 and substrate W. The anode mask 25 is a substantially plate-like member made, for example, of a dielectric material and is installed on a front face of the anode holder 20. The front face of the anode holder 20 here is a face on the side facing the substrate holder 40. That is, the anode mask 25 is placed between the anode 21 and substrate holder 40. The anode mask 25 has an opening 25 a (which is an example of a second opening) in an approximate central portion thereof, where an electric current flowing between the anode 21 and substrate W passes through the opening 25 a. Preferably the opening 25 a is smaller in diameter than the anode 21. As described later, the diameter of the opening 25 a in the anode mask 25 is configured to be adjustable.

The anode mask 25 has an anode mask mount 25 b on its outer circumference to mount the anode mask 25 integrally on the anode holder 20. Note that the position of the anode mask 25 can be between the anode holder 20 and substrate holder 40, but preferably the anode mask 25 is closer to the anode holder 20 than the intermediate position between the anode holder 20 and substrate holder 40. Also, for example, the anode mask 25 may be placed on the front face of the anode holder 20 without being mounted on the anode holder 20. However, when the anode mask 25 is attached to the anode holder 20 as with the present embodiment, the position of the anode mask 25 relative to the anode holder 20 is fixed, making it possible to prevent displacement between the position of the anode 21 and position of the opening 25 a.

Preferably the anode 21 held by the anode holder 20 is an insoluble anode. When the anode 21 is an insoluble anode, the anode 21 does not dissolve even when the plating process progresses, and the shape of the anode 21 remains unchanged. Consequently, since the positional relationship (distance) between the anode mask 25 and anode 21 does not change, it is possible to prevent changes in the electric field between the anode 21 and substrate W, which would be caused by changes in the positional relationship between the anode mask 25 and a surface of anode 21.

The plating apparatus 10 further includes a regulation plate 60 adapted to adjust the electric field between the anode 21 and substrate W. The regulation plate 60 is a substantially flat-plate member made, for example, of a dielectric material and is installed between the anode mask 25 and substrate holder 40 (substrate W). The regulation plate 60 includes an opening 60 a (which is an example of a first opening) adapted to allow passage of the electric current flowing between the anode 21 and substrate W. Preferably the opening 60 a is smaller in diameter than the substrate W. As described later, the diameter of the opening 60 a in the regulation plate 60 is configured to be adjustable.

Preferably the regulation plate 60 is closer to the substrate holder 40 than the intermediate position between the anode holder 20 and substrate holder 40. The closer to the substrate holder 40 the regulation plate 60 is placed, the more accurately the film thickness on the periphery of the substrate W can be controlled by adjusting the diameter of the opening 60 a in the regulation plate 60.

A paddle 18 is installed between the regulation plate 60 and substrate holder 40 to stir the plating solution Q near the surface-to-be-plated W1 of the substrate W. The paddle 18 is a substantially rod-shaped member and is installed in the plating treatment bath 52, extending in a vertical direction. One end of the paddle 18 is fixed to a paddle drive unit 19. The paddle 18 is moved by the paddle drive unit 19 horizontally along the surface-to-be-plated W1 of the substrate W, thereby stirring the plating solution Q.

Next, the anode mask 25 shown in FIG. 1 will be described in detail. FIGS. 2 and 3 are schematic front views of the anode mask 25. FIG. 2 shows the anode mask 25 when the diameter of the opening 25 a is comparatively large. FIG. 3 shows the anode mask 25 when the diameter of the opening 25 a is comparatively small. Here, the smaller the opening 25 a in the anode mask 25, the more heavily the electric current flowing from the anode 21 to the substrate W is concentrated on the central portion of the surface-to-be-plated W1 of the substrate W. Thus, as the opening 25 a is reduced in size, the film thickness in the central portion of the surface-to-be-plated W1 of the substrate W tends to increase.

As shown in FIG. 2, the anode mask 25 has a rim 26 substantially annular in shape. In FIG. 2, the diameter size of the opening 25 a in the anode mask 25 is maximized. In this case, the diameter of the opening 25 a coincides with the inside diameter of the rim 26.

As shown in FIG. 3, the anode mask 25 includes plural aperture blades 27 (which is an example of an adjustment mechanism) configured to be able to adjust the opening 25 a. The aperture blades 27 define the opening 25 a in collaboration with one another. Being structured similarly to an aperture mechanism of a camera, the aperture blades 27 together increase and decrease the diameter of the opening 25 a (adjust the diameter of the opening 25 a). The opening 25 a in the anode mask 25 shown in FIG. 3 is formed into a non-circular shape (e.g., polygonal shape) by means of the aperture blades 27. In this case, the diameter of the opening 25 a corresponds to the shortest distance between opposite sides of the polygon or the diameter of an inscribed circle. Alternatively, the diameter of the opening 25 a can be defined by the diameter of a circle having an area equivalent to the area of the opening. Note that the distance between anode 21 and that face of the aperture blade 27 which faces the anode 21 is, for example, between 0 mm and 8 mm (both inclusive).

The aperture blades 27 are used in conjunction, for example, to manually increase and decrease the diameter of the opening 25 a. Also, the aperture blades 27 may be configured to be driven together by means of pneumatic pressure or an electric driving force. The adjustment mechanism which uses the aperture blades 27 features the capability to make the opening 25 a variable in a comparatively wide range. Also, when the substrate is circular, desirably the opening 25 a in the anode mask 25 is circular. However, with the opening 25 a whose diameter is variable in a comparatively wide range, it is mechanically difficult to maintain a completely circular shape in an entire range of the opening 25 a from minimum diameter to maximum diameter. Generally, when the opening adapted to allow the passage of the electric current flowing between the anode 21 and substrate W is not completely circular, an azimuth distribution in an electric field becomes nonuniform and consequently the shape of the opening may be transferred to a thickness distribution of a plating film formed on the periphery of the substrate W. However, since the anode mask 25 is mounted integrally on the anode holder 20, allowing a sufficient distance from the substrate, the influence on the plating film thickness distribution can be minimized even when the opening is not completely circular.

Next, the regulation plate 60 shown in FIG. 1 will be described in detail. FIG. 4 shows a perspective front view of the regulation plate 60, of which a diameter of an opening 60 a is comparatively large, and FIG. 5 shows a perspective rear view of the regulation plate 60, of which the diameter of the opening 60 a is comparatively large. Also, FIG. 6 shows a front perspective view of the regulation plate 60, of which the diameter of the opening 60 a is comparatively small.

As shown in FIGS. 4 to 6, the regulation plate 60 includes a plate main body 61 which has a substantially flat-plate shape. The plate main body 61 has a pair of suspension parts 62 in upper right and left end portions to suspend the regulation plate 60 on edges of a plating treatment bath 52 shown in FIG. 1. Also, the plate main body 61 has an opening 60 a in an approximate central portion thereof. The opening 60 a is formed by an opening adjustment portion 63 provided in the plate main body 61.

As shown in FIG. 5, a rotating member 100 making up part of the opening adjustment portion 63 is mounted on a back side of the regulation plate 60. Also, as shown in FIG. 6, the regulation plate 60 includes a blade body 70 configured to narrow the diameter of the opening 60 a. Details of the rotating member 100 and blade body 70 will be described later.

FIG. 7 is an exploded perspective view of the regulation plate 60. As shown in FIG. 7, the regulation plate 60 includes the plate main body 61, the blade body 70, a ring member 80, a blade presser member 90, the rotating member 100, and a protective member 110. The blade body 70, ring member 80, blade presser member 90, rotating member 100, and protective member 110 make up the opening adjustment portion 63. Also, the regulation plate 60 includes a rim 64 configured to form the opening 60 a in conjunction with the plate main body 61.

The blade body 70 is located on a front side of the rim 64 of the regulation plate 60 and is provided with plural first blades 71 used to narrow the diameter of the opening 60 a. Note that according to the present embodiment, the front side of the regulation plate 60 corresponds to the plane opposed to the substrate holder 40 shown in FIG. 1. However, in another embodiment, the regulation plate 60 may be placed in the plating treatment bath 52 shown in FIG. 1 such that the front side of the regulation plate 60 will be opposed to the anode holder 20 shown in FIG. 1.

The ring member 80 is configured to translate the plural first blades 71 in the radial direction of the opening 60 a. The ring member 80 is placed along the rim 64 of the regulation plate 60. According to the present embodiment, the ring member 80 is placed along an inner circumferential surface of the rim 64 of the regulation plate 60. However, this is not restrictive, and the ring member 80 may be placed, for example, on a front side of the rim 64 of the regulation plate 60.

The blade presser member 90 is placed on a front side of the blade body 70 (on a side opposite the ring member 80). The rotating member 100 is placed on a rear side of the plate main body 61 and integrated with the ring member 80 as described later. Members making up regulation plate 60 will be described in detail below.

FIG. 8 shows a perspective front view of the plate main body 61, and FIG. 9 shows a perspective rear view of the plate main body 61. As shown in FIG. 8, the plate main body 61 is a substantially flat-plate member and has the opening 60 a in an approximate central portion thereof. The rim 64 having substantially a same opening as the opening 60 a is fixed on a front side of the plate main body 61. The rim 64 forms the opening 60 a in conjunction with the plate main body 61. As shown in FIG. 9, the plate main body 61 has plural pin holes 65 on a rear side, to insert support pins adapted to slidably support the rotating member 100. Also, the rim 64 has plural screw holes 66 on a front side to accept screws for use to fix the blade presser member 90 and protective member 110.

FIG. 10 is a drawing showing a perspective front view of the ring member 80. As described above, the ring member 80 is placed along an inner circumferential surface of the opening 60 a in the plate main body 61 shown in FIGS. 8 and 9. Therefore, an outside diameter of the ring member 80 is configured to approximately coincide with an inside diameter of the rim 64 forming the opening 60 a in the plate main body 61. Consequently, an inside diameter of the ring member 80 equals a maximum inside diameter of the opening 60 a. As illustrated, the ring member 80 (which is an example of a first moving mechanism) has plural slide slots 81 on the front side. According to the present embodiment, eight slide slots 81 corresponding to the number of first blades 71 making up the blade body 70 is provided in the ring member 80. The slide slots 81 may or may not penetrate toward a rear side of the ring member 80. The slide slots 81 are configured to incline in the radial direction of the opening 60 a. In other words, the slide slots 81 are placed being inclined such that a longitudinal direction of the slide slots will not face a center of the opening 60 a. The slide slots 81 are provided in the ring member 80 in such a way as to be rotationally symmetric about a central axis of the opening 60 a. According to the present embodiment, since eight slide slots 81 are provided, the slide slots 81 have eight-fold rotational symmetry.

FIG. 11 shows a perspective front view of the rotating member 100. The rotating member 100 includes a ring portion 101 and a flat-plate lever portion 102 attached to the ring portion 101. The ring portion 101 is fixed on the rear side of the ring member 80 shown in FIG. 10. An inside diameter of the ring portion 101 is configured to substantially coincide in inside diameter with the ring member 80. The lever portion 102 is coupled to an outer circumferential portion of the ring portion 101, and when the lever portion 102 is swung in a circumferential direction of the ring portion 101, the ring portion 101 rotates in the circumferential direction within a range of a swing angle.

Four projections 104 are provided on a circumference of the ring portion 101, and a support slot 103 is formed in each of the projections 104 along the circumferential direction of the ring portion 101. As described later, the support slots 103 are slidably supported by support pins fixed to the pin holes 65 in the plate main body 61 shown in FIG. 9.

FIG. 12 shows a perspective front view of a first blade 71 making up the blade body 70. As illustrated, the first blade 71 is a fan-shaped member whose inner peripheral edge is formed into an arc shape. As shown in FIG. 7, the first blade 71 is overlapped with other first blades 71, forming a substantially circular inner peripheral edge of the blade body 70 as a whole. According to the present embodiment, the blade body 70 is made up of eight first blades 71, but this is not restrictive, and the blade body 70 can be made up of any number of first blades 71.

A slide pin 72 configured to slide along a slide slot 81 in the ring member 80 shown in FIG. 10 is provided on a rear side of the first blade 71. Although in the present embodiment, a single slide pin 72 is provided on the first blade 71, this is not restrictive, and two or more slide pins 72 may be provided on the first blade 71. In this case, the number of slide slots 81 in the ring member 80 shown in FIG. 10 needs to be set equal to the number of slide pins 72.

Also, guide pins 73 configured to slide along guide slots 91 in the blade presser member 90 shown in FIG. 13 described later are provided on a front side of the first blade 71. Although in the present embodiment, two guide pins 73 are provided on the first blade 71, this is not restrictive, and one or three or more guide pins 73 may be provided on the first blade 71.

FIG. 13 is a perspective front view of the blade presser member 90. The blade presser member 90 is a substantially flat-plate member and the opening 60 a is formed in an approximate central portion thereof. The diameter of the opening 60 a in the blade presser member 90 is substantially equal to the inside diameter of the ring member 80 shown in FIG. 10. The blade presser member 90 has plural guide slots 91. According to the present embodiment, sixteen guide slots 91 are provided in the blade presser member 90 and two guide slots 91 correspond, respectively, to the two guide pins 73 on the first blade 71 shown in FIG. 12. The number of guide slots 91 can be changed appropriately according to the number of guide pins 73. The guide slots 91 are formed in parallel to a translation direction of the first blades 71. Also, the blade presser member 90 has plural screw holes 92. When the screw holes 92 are aligned with the screw holes 66 formed in the rim 64 of the plate main body 61 shown in FIG. 8 and screws are screwed into the screw holes, the blade presser member 90 can be fixed to the plate main body 61.

The blade presser member 90 is placed such that a rear side of the blade presser member 90 will be put in contact with the front side of the blade body 70. Therefore, when performing translational movement in the radial direction of the opening 60 a, the first blades 71 of the blade body 70 perform translational movement in contact with the blade presser member 90. To reduce abrasion of the blade presser member 90 and first blades 71, preferably the blade presser member 90 is made, for example, of a low-friction resin such as PTFE.

FIG. 14 is a perspective front view of the protective member 110. The protective member 110 is a substantially flat-plate member and the opening 60 a is formed in an approximate central portion thereof. The diameter of the opening 60 a in the protective member 110 is substantially equal to the inside diameter of the ring member 80 shown in FIG. 10. The protective member 110 is placed on a front side of the blade presser member 90. The protective member 110 has plural screw holes 111. When the screw holes 111 are aligned with the screw holes 66 shown in FIG. 8 and screw holes 92 shown in FIG. 13 and screws are screwed into the screw holes, the protective member 110 can be fixed to the plate main body 61. The protective member 110 is made, for example, of vinyl chloride or the like, and protects the front side of the blade presser member 90.

Next, a mechanism for translating the first blade 71 shown in FIG. 12 will be described in detail. FIG. 15 is a partial front view of the regulation plate 60 as viewed from the front side. FIG. 15 shows the rotating member 100, plural first blades 71, blade presser member 90, and slide slots 81 in the ring member 80 as seen one through another, and other members are omitted for simplicity of illustration.

As shown in FIG. 15, each of the plural first blades 71 is placed so as to partially overlap other first blades 71, forming overlapping portions 75. The inner peripheral edges of the plural first blades 71 form a substantially circular shape. In the illustrated state, the slide pins 72 on the plural first blades 71 are located in intermediate part of the respective slide slots 81 and the guide pins 73 are located in intermediate part of the respective guide slots 91. In the illustrated state, the inside diameter formed by the inner peripheral edges of the plural first blades 71 is smaller than an inside diameter of the opening 60 a in the regulation plate 60. Therefore, the plural first blades 71 reduce the inside diameter of the opening 60 a in the regulation plate 60.

When the lever portion 102 of the rotating member 100 moves in the direction of arrow A1 or A2, i.e., in the circumferential direction of the ring portion 101, the non-illustrated ring member 80 coupled to the ring portion 101 also rotates in the circumferential direction. For example, when the lever portion 102 moves in the direction of arrow A1 (clockwise in FIG. 15), the ring member 80 rotates clockwise. Consequently, the slide pins 72 on the first blades 71 slide in the slide slots 81 and minimum diameter portions 81 a of the slide slots 81 move toward the slide pins 72. As the minimum diameter portions 81 a of the slide slots 81 move toward the slide pins 72, the first blades 71 move inward in the radial direction of the opening 60 a. Since the guide pins 73 on the first blades 71 slide in the guide slots 91, circumferential movement and rotary motion of the first blades 71 are prevented. Therefore, the first blades 71 can reliably perform translational movement in the radial direction.

Also, for example, when the lever portion 102 moves in the direction of arrow A2 (counterclockwise in FIG. 15), the ring member 80 rotates counterclockwise. Consequently, the slide pins 72 on the first blades 71 slide in the slide slots 81 and maximum diameter portions 81 b of the slide slots 81 move toward the slide pins 72. As the maximum diameter portions 81 b of the slide slots 81 move toward the slide pins 72, the first blades 71 perform translational movement outward in the radial direction of the opening 60 a.

The plural first blades 71 perform translational movement in the radial direction similarly to one another. Therefore, the plural first blades can move in the radial direction while maintaining an angular relationship among the first blades 71. Consequently, a perfectly circular shape formed by the inner peripheral edges of the plural first blades 71 can be maintained better than when plural aperture blades rotate around a predetermined axis, reducing the diameter of the opening as with an aperture mechanism of a camera.

FIG. 16 is a rear view of the regulation plate 60 when the inside diameter of the opening 60 a is at the maximum and FIG. 17 is a rear view of the regulation plate 60 when the inside diameter of the opening 60 a is at the minimum. As shown in FIG. 16, when the inside diameter of the opening 60 a in the regulation plate 60 is at the maximum, the lever portion 102 of the rotating member 100 is located relatively to the right and has its range of movement restricted by a stopper 67 provided on the plate main body 61. In the state illustrated in FIG. 16, the non-illustrated first blades 71 are located at an outermost position in the radial direction of the opening 60 a and the inner peripheral edges of the first blades 71 substantially coincide with an inner peripheral edge of the ring portion 101 of the rotating member 100.

Four support pins 105 are provided on the plate main body 61. The support pins 105 slidably engage with the support slots 103 provided in the projections 104 on the ring portion 101. Consequently, when the lever portion 102 is operated, the ring portion 101 is guided to rotate in the circumferential direction along the support slots 103.

As shown in FIG. 17, when the inside diameter of the opening 60 a in the regulation plate 60 is at the minimum, the lever portion 102 of the rotating member 100 is located relatively to the left and has its range of movement restricted by a stopper 67 provided on the plate main body 61. In the state illustrated in FIG. 17, the plural first blades 71 are located at an innermost position in the radial direction of the opening 60 a and the first blades 71 reduce the opening 60 a in the regulation plate 60.

The lever portion 102 may be operated, for example, automatically by a mechanical actuator or manually by an operator. Also, the lever portion 102 can be fixed at any position between the pair of stoppers 67.

As described above, the regulation plate 60 according to the present embodiment allows the diameter of the opening 60 a to be adjusted by narrowing the diameter of the opening 60 a using the plural first blades 71. This makes it possible to curb reduction in in-plane uniformity due to influence of a terminal effect when the first substrate and second substrate differ from each other in characteristics or processing conditions. Specifically, in plating the substrate under conditions in which the influence of the terminal effect appears prominently, by reducing the diameter of the opening a in the regulation plate 60, the film deposition rate on the periphery of the substrate can be slowed down, making it possible to improve the in-plane uniformity on the substrate. Also, since the first blades 71 are configured to perform translational movement, the plural first blades 71 can move in the radial direction while maintaining an angular relationship among the first blades 71. Therefore, a perfectly circular shape formed by the inner peripheral edges of the plural first blades 71 can be maintained better than when plural aperture blades rotate around a predetermined axis, reducing the diameter of the opening as with an aperture mechanism of a camera.

Note that according to the present embodiment, the first blades 71 have the slide pins 72 while the ring member 80 has the slide slots 81. However, this is not restrictive, and the ring member 80 may have slide pins 72 and the first blades 71 may have corresponding slide slots 81. Even when the first blades 71 and ring member 80 are configured in this way, as the ring member 80 rotates in the circumferential direction, the slide pins 72 slide in the slide slots 81, allowing the first blades 71 to move in the radial direction.

According to the present embodiment, the first blades 71 have the guide pins 73 and the blade presser member 90 have the guide slots 91. However, this is not restrictive, and the blade presser member 90 may have the guide pins 73 and the first blades 71 may have corresponding guide slots 91. Even when the first blades 71 and blade presser member 90 are configured in this way, as the first blades 71 are moved by the ring member 80, the guide pins 73 slide in the guide slots 91, making it possible to prevent circumferential movement and rotary motion of the first blades 71.

According to the present embodiment, the projections 104 provided with the support slots 103 are formed on the ring portion 101 of the rotating member 100 and the support pins 105 are fixed to the plate main body 61. However, this is not restrictive, and the ring portion 101 of the rotating member 100 may have support pins 105 and the plate main body 61 may have corresponding support slots 103. Even when the rotating member 100 and plate main body 61 are configured in this way, as the ring portion 101 is swung by the lever portion 102, the support pins 105 slide in the support slots 103, allowing the ring portion 101 to rotate in the circumferential direction.

Furthermore, according to the present embodiment, the regulation plate 60 includes only the blade body 70 (plural first blades 71) as a means of reducing the diameter of the opening 60 a. However, the regulation plate 60 may include plural second blades other than the plural first blades 71, and a mechanism for translating the plural second blades. In this case, the plural second blades are placed at a position shifted from the plural first blades 71 in a direction orthogonal to the radial direction of the opening 60 a. The mechanism for translating the plural second blades is identical with the above-mentioned mechanism for translating the plural first blades 71, and consequently the plural second blades perform translational movement in the radial direction of the opening 60 a. Concrete examples will be described below with reference to drawings.

FIG. 18 is a perspective front view of a regulation plate having plural first blades and plural second blades according to another embodiment, and FIG. 19 is a perspective rear view of the regulation plate. In the drawings described below, components corresponding to those shown in FIGS. 4 to 17 are denoted by the same reference numerals as those used in FIGS. 4 to 17 with either “A” or “B” added to the end of the numerals, and redundant description thereof will be omitted.

As shown in FIGS. 18 and 19, the regulation plate 60 according to the present embodiment includes a first plate main body 61A and a second plate main body 61B. The first plate main body 61A includes a first opening adjustment portion 63A and the second plate main body 61B includes a second opening adjustment portion 63B. The first plate main body 61A and second plate main body 61B are coupled together by arbitrary fixing means 120 such as screws or bolts. In the illustrated regulation plate 60, the first plate main body 61A and second plate main body 62B are coupled together by the fixing means 120, being placed in close contact without a gap therebetween. However, this is not restrictive, and the first plate main body 61A and second plate main body 62B may be coupled together with a gap therebetween. Also, the fixing means 120 may include an adjustment mechanism adapted to adjust size of the gap between the first plate main body 61A and second plate main body 62B. This will make it possible to adjust a distance between after-mentioned plural first blades 71A (see FIG. 21) and plural second blades 71B (see FIG. 22) as desired.

The first plate main body 61A includes an opening portion 69A used to expose a handle 105A of a rotating member 100A to the outside. Also, the second plate main body 61B includes an opening portion 69B used to expose a handle 105B of a rotating member 100B to the outside. The handle 105A exposed from the opening portion 69A and the handle 105B exposed from the opening portion 69B can be operated independently of each other by any actuator or by hand. This makes it possible to translate the plural first blades 71A shown in FIG. 21 and the plural second blades 71B in the radial direction independently of each other.

FIG. 20 is an exploded perspective view of the first plate main body 61A and second plate main body 62B. As illustrated, the first plate main body 61A and second plate main body 62B are coupled together in such a way that a plane on which the rotating member 100A is provided and a plane on which the rotating member 100B is provided will be opposed to each other. The first plate main body 61A includes a cavity 68A capable of housing the rotating member 100A and rotating member 100B. The cavity 68A is configured to house the rotating member 100A and rotating member 100B when the first plate main body 61A and second plate main body 62B are coupled together.

The first plate main body 61A has a first opening 169A in an approximate central portion thereof to allow passage of an electric current. Also, the second plate main body 61B has a second opening 169B in an approximate central portion thereof to allow passage of an electric current. The first plate main body 61A and second plate main body 61B are coupled together in such a way that a center of the first opening 169A and a center of the second opening 169B will be concentric. In other words, the first plate main body 61A and second plate main body 61B are coupled together in such a way that a straight line joining the center of the first opening 169A and the center of the second opening 169B will be orthogonal to radial directions of the respective openings.

FIG. 21 is an exploded perspective view of the first plate main body 61A. As illustrated, the first plate main body 61A includes a blade body 70A, a ring member 80A, a blade presser member 90A, the rotating member 100A, and a protective member 110A. According to the present embodiment, each of the plural first blades 71A making up the blade body 70 has two slide pins 72A. The ring member 80A has slide slots 81A in pairs corresponding to the two slide pins 72A.

FIG. 22 is an exploded perspective view of the second plate main body 61B. As illustrated, the second plate main body 61B includes a blade body 70B, a ring member 80B, a blade presser member 90B, the rotating member 100B, and a protective member 110B. According to the present embodiment, each of the plural second blades 71B making up the blade body 70 has two slide pins 72B. The ring member 80B has slide slots 81B in pairs corresponding to the two slide pins 72B.

The first plate main body 61A and second plate main body 61B are coupled together in such a way that a center of an opening formed by the plural first blades 71A shown in FIG. 21 and a center of an opening formed by the plural second blades 71B shown in FIG. 22 will be concentric. In other words, the first plate main body 61A and second plate main body 61B are coupled together in such a way that a straight line joining the center of the opening formed by the plural first blades 71A and the center of the opening formed by the plural second blades 71B will be orthogonal to radial directions of the respective openings.

In this way, the regulation plate 60 provided with the plural first blades 71A and plural second blades 71B allows the diameter of the opening 60 a to be narrowed by both the plural first blades 71A and plural second blades 71B. In this case, the plural first blades 71A and plural second blades 71B allow the film deposition rate on the periphery of the substrate to be further slowed down. This makes it possible to improve the in-plane uniformity on the substrate whose film thicknesses tends to increase on the periphery.

When installing plural conventional regulation plates in a plating bath, it is necessary to position the center of an opening with respect to each of the plural regulation plates, taking a lot of trouble. In contrast, when plural first blades 71A and plural second blades 71B can be installed in a common regulation plate 60, the center of the opening formed by the first blades 71A and the center of the opening formed by the second blades 71B are fixed relatively. Therefore, when positioning the regulation plate 60 in a plating bath, there is no need to position the center of the opening formed by the plural first blades 71A and the center of the opening formed by the plural second blades 71B separately. Consequently, even when high accuracy is required of the center position of the opening in the regulation plate 60, the regulation plate 60 can be positioned easily.

Also, since the blade body 70A of the regulation plate 60 is made up of the plural first blades 71A, the shape of the opening of the blade body 70A is not perfectly circular in a strict sense. Consequently, it is difficult to completely remove variations in an electric field applied to the substrate W, where the variations are caused by the shape of the opening. However, since the plural second blades 71B are provided, electric field variations caused by the opening shape formed by the plural first blades 71A and electric field variations caused by the opening shape formed by the plural second blades 71B cancel out each other, reducing the electric field variations and making it possible to bring the plating film formed on the substrate W close to a perfect circle.

Furthermore, in the regulation plate 60, as shown in FIG. 15, each of the plural first blades 71 has the overlapping portions 75 with the adjacent first blades 71 and a portion not overlapping the adjacent first blades 71. The overlapping portions 75 are thicker than the non-overlapping portion, and consequently differ in electric field suppression effect from the non-overlapping portion. This can result in electric field variations in the circumferential direction of the opening. On the other hand, when the regulation plate 60 has the plural second blades 71B in addition to the plural first blades 71A, by shifting circumferential positions of the overlapping portions of the plural second blades 71B from circumferential positions of the overlapping portions of the plural first blades 71A, it is possible to reduce the electric field variations caused by the respective overlapping portions of the first blades and second blades. Preferably if the circumferential positions of the overlapping portions of the plural second blades 71B and the circumferential positions of the overlapping portions of the plural first blades 71A are arranged in a staggered manner, the electric field variations can be reduced further.

Also, in the regulation plate 60 provided with the plural first blades 71A and plural second blades 71B, the diameter of the opening 60A defined by the plural first blades 71A and the diameter of the opening 60B defined by the plural second blades 71B can be made different from each other. This makes it possible to decrease the diameters of the openings in stages according to the characteristics or processing conditions of the substrate, such as reducing the diameter of the opening defined by the blades closer to the substrate and increasing the diameter of the opening defined by the blades farther from the substrate.

Next, description will be given of the process of plating the substrate W using the plating apparatus 10 shown in FIG. 1. As described above, the influence of the terminal effect varies with characteristics of the substrate W, conditions for processing the substrate W, and the like. Therefore, when plural substrates W differing in the influence of the terminal effect are plated using a single plating apparatus 10, in order to curb the reduction in the in-plane uniformity of film thickness due to the terminal effect, it is necessary to adjust the electric field applied to each substrate W, according to the characteristics of the substrate W, conditions for processing the substrate W, and the like.

By adjusting the diameter of at least the opening 25 a in the anode mask 25 according to the characteristics of the substrates W or conditions for processing the substrates W, the plating apparatus 10 of the present embodiment can curb the reduction in the in-plane uniformity of the plating film on the substrates W.

Specifically, when the resist aperture ratio of the second substrate is lower than the resist aperture ratio of the first substrate, as described above, even if a plating film is formed on the second substrate, variation in the electrical resistance value between the central portion of the second substrate and the electrical contact is smaller than in the case of the first substrate whose resist aperture ratio is comparatively high. Consequently, even if a plating film is formed to some extent on the second substrate, the influence of the terminal effect on the second substrate remains large. Therefore, when the first substrate and second substrate are plated by keeping the conditions other than the resist aperture ratios of the substrates equal, the film thickness of the second substrate becomes larger in a peripheral portion of the substrate and relatively smaller in the central portion the substrate than the film thickness of the first substrate. Thus, the diameter of the opening 25 a in the anode mask 25 is set smaller when the second substrate is plated using the plating apparatus 10 than when the first substrate is plated. This makes it possible to increase the film thickness in the central portion of the second substrate. Consequently, the reduction in in-plane uniformity due to the influence of the terminal effect can be curbed on both the first substrate and second substrate.

Also, when a seed layer of the second substrate is thinner than a seed layer of the first substrate, the terminal effect on the second substrate becomes prominent as described above. Therefore, when the first substrate and second substrate are plated by keeping the conditions other than the thickness of the seed layer equal, the film thickness of the second substrate becomes larger in the peripheral portion of the substrate and relatively smaller in the central portion the substrate than the film thickness of the first substrate. Thus, the diameter of the opening 25 a in the anode mask 25 is set smaller when the second substrate is plated using the plating apparatus 10 than when the first substrate is plated. This makes it possible to increase the film thickness in the central portion of the second substrate. Consequently, the reduction in in-plane uniformity due to the influence of the terminal effect can be curbed on both the first substrate and second substrate.

Furthermore, when the second substrate is plated using a plating solution with a lower electrical resistance value than the plating solution used for the first substrate, the terminal effect on the second substrate becomes prominent as described above. Therefore, when the first substrate and second substrate are plated by keeping the conditions other than the electrical resistance value equal, the film thickness of the second substrate becomes larger in the peripheral portion of the substrate and relatively smaller in the central portion the substrate than the film thickness of the first substrate. Thus, the diameter of the opening 25 a in the anode mask 25 is set smaller when the second substrate is plated using the plating apparatus 10 than when the first substrate is plated. This makes it possible to increase the film thickness in the central portion of the second substrate. Consequently, the reduction in in-plane uniformity due to the influence of the terminal effect can be curbed on both the first substrate and second substrate.

Furthermore, by adjusting the diameter of the opening 60 a in the regulation plate 60 in addition to adjusting the diameter of the opening 25 a in the anode mask 25, the plating apparatus 10 of the present embodiment can improve the in-plane uniformity of the plating film on the substrate W.

The regulation plate 60 is placed at a position closer to the substrate W than to the anode mask 25. Consequently, a plating current passing through the opening 60 a in the regulation plate 60 becomes less prone to spread to the periphery of the substrate W. Thus, if the diameter of the opening 60 a in the regulation plate 60 is decreased, the film thickness on the periphery of the substrate W can be decreased, and if the diameter of the opening 60 a in the regulation plate 60 is increased, the film thickness on the periphery of the substrate W can be increased.

Preferably the diameter of the opening 60 a in the regulation plate 60 is adjusted as appropriate according to the film thickness distribution on the substrate W, which is changed by adjusting the diameter of the opening 25 a in the anode mask 25. Therefore, in plating a second substrate differing from a first substrate in characteristics or processing conditions, the diameter of the opening 25 a in the anode mask 25 is adjusted to be smaller or larger than when the first substrate is processed and the diameter of the opening 60 a in the regulation plate 60 is changed as appropriate. When the regulation plate 60 has plural first blades 71A and plural second blades 71B such as shown in FIGS. 18 to 22, the opening portions 69A and 69B formed by the first and second blades, respectively, can be changed independently of each other as appropriate. This provides an equipment configuration capable of more accurately controlling reduction in in-plane uniformity due to influence of a terminal effect when plating plural substrates differing in characteristics and processing conditions.

Next, a concrete description will be given of changes in profiles of plating films on substrates W, where the profiles are changed by changing the diameter of the opening 25 a in the anode mask 25 and the diameter of the opening 60 a in the regulation plate 60. Examples in which the regulation plate 60 shown in FIGS. 4 to 17 is used will be shown below.

FIG. 23 is a diagram showing profiles of plating films on substrates W with a high resist aperture ratio (80%) and substrates W with a low resist aperture ratio (10%). In FIG. 23, “AM” denotes the diameter of the opening 25 a in the anode mask 25, “RP” denotes the diameter of the opening 60 a in the regulation plate 60, HDP denotes a substrate W with a high resist aperture ratio, and LDP denotes a substrate W with a low resist aperture ratio. Note that both the substrates W with a high resist aperture ratio and substrates W with a low resist aperture ratio are 50 nm to 100 nm in seed layer thickness and that the profiles in FIG. 23 are obtained using a solution with a comparatively low resistance for plating.

As illustrated in FIG. 23, when the substrate W with a high resist aperture ratio is plated with the diameter of the opening 25 a set to 230 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition A), the film thickness in the central portion of the substrate is large and the film thicknesses on the periphery of the substrate is small. In contrast, when the substrate W with a high resist aperture ratio is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition C), since the diameter of the opening 25 a is larger under condition C than under condition A, the film thickness in the central portion of the substrate is smaller. Also, when the substrate W with a high resist aperture ratio is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 280 mm (hereinafter this condition will be referred to as condition B), since the diameter of the opening 60 a is larger under condition B than under condition C, the film thicknesses on the periphery of the substrate is larger.

When the substrate W with a low resist aperture ratio is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition E), the film thickness in the central portion of the substrate is small and the film thicknesses on the periphery of the substrate is large. This means that the film thickness on the periphery of the substrate has been increased under the influence of the terminal effect. In contrast, when the substrate W with a low resist aperture ratio is plated with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition F), since the diameter of the opening 25 a is smaller under condition F than under condition E, the film thickness in the central portion of the substrate is larger. Also, when the substrate W with a low resist aperture ratio is plated with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 274 mm (hereinafter this condition will be referred to as condition D), since the diameter of the opening 60 a is smaller under condition D than under condition F, the film thicknesses on the periphery of the substrate is smaller.

As shown in FIG. 23, even in the case of the substrates W with a low resist aperture ratio on which the influence of the terminal effect appears comparatively prominently, if the diameter of the opening 25 a is set smaller than the diameter (270 mm: conditions B and C) of the opening 25 a suitable for plating of the substrates W with a high resist aperture ratio, it is possible to curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see conditions D and F). Furthermore, by adjusting the diameter of the opening 60 a in the regulation plate 60, the film thickness on the periphery of the substrate W can be adjusted, making it possible to further curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see condition D).

FIG. 24 is a diagram showing profiles of plating films on substrates W with a thick seed layer (500 nm or above) and substrates W with a thin seed layer (50 to 100 nm). Note that both the substrates W with a thick seed layer and substrates W with a thin seed layer have a resist aperture ratio of 10% and that the profiles in FIG. 24 are obtained using a solution with a comparatively low resistance for plating.

As illustrated in FIG. 24, when the substrate W with a thick seed layer is plated with the diameter of the opening 25 a set to 230 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition A), the film thickness in the central portion of the substrate is large and the film thicknesses on the periphery of the substrate is small. In contrast, when the substrate W with a thick seed layer is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition C), since the diameter of the opening 25 a is larger under condition C than under condition A, the film thickness in the central portion of the substrate is smaller. Also, when the substrate W with a thick seed layer is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 278 mm (hereinafter this condition will be referred to as condition B), since the diameter of the opening 60 a is larger under condition B than under condition C, the film thicknesses on the periphery of the substrate is larger.

When the substrate W with a thin seed layer is plated with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition E), the film thickness in the central portion of the substrate is small and the film thicknesses on the periphery of the substrate is large. This means that the film thickness on the periphery of the substrate has been increased under the influence of the terminal effect. In contrast, when the substrate W with a thin seed layer is plated with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition F), since the diameter of the opening 25 a is smaller under condition F than under condition E, the film thickness in the central portion of the substrate is larger. Also, when the substrate W with a thin seed layer is plated with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 274 mm (hereinafter this condition will be referred to as condition D), since the diameter of the opening 60 a is smaller under condition D than under condition F, the film thicknesses on the periphery of the substrate is smaller.

As shown in FIG. 24, even in the case of the substrates W with a thin seed layer on which the influence of the terminal effect appears comparatively prominently, if the diameter of the opening 25 a is set smaller than the diameter (270 mm: conditions B and C) of the opening 25 a suitable for plating of the substrates W with a thick seed layer, it is possible to curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see conditions D and F). Furthermore, by adjusting the diameter of the opening 60 a in the regulation plate 60, the film thickness on the periphery of the substrate W can be adjusted, making it possible to further curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see condition D).

FIG. 25 is a diagram showing profiles of plating films on substrates W plated in a plating solution (type A) having a comparatively high electrical resistance and substrates W plated in a plating solution (type B) having a comparatively low electrical resistance. Note that both the substrates W plated in a plating solution having a comparatively high electrical resistance and substrates W plated in a plating solution having a comparatively low electrical resistance have a resist aperture ratio of 10% and have a seed layer thickness of 50 nm to 100 nm.

As illustrated in FIG. 25, when the substrate W is plated in a plating solution having a comparatively high electrical resistance with the diameter of the opening 25 a set to 230 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition A), the film thickness in the central portion of the substrate is large and the film thicknesses on the periphery of the substrate is small. In contrast, when the substrate W is plated in a plating solution having a comparatively high electrical resistance with the diameter of the opening 25 a set to 260 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition C), since the diameter of the opening 25 a is larger under condition C than under condition A, the film thickness in the central portion of the substrate is smaller. Also, when the substrate W is plated in a plating solution having a comparatively high electrical resistance with the diameter of the opening 25 a set to 260 mm and with the diameter of the opening 60 a set to 272 mm (hereinafter this condition will be referred to as condition B), since the diameter of the opening 60 a is smaller under condition B than under condition C, the film thicknesses on the periphery of the substrate is smaller.

When the substrate W is plated in a plating solution having a comparatively low electrical resistance with the diameter of the opening 25 a set to 270 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition E), the film thickness in the central portion of the substrate is small and the film thicknesses on the periphery of the substrate is large. This means that the film thickness on the periphery of the substrate has been increased under the influence of the terminal effect. In contrast, when the substrate W is plated in a plating solution having a comparatively low electrical resistance with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 276 mm (hereinafter this condition will be referred to as condition F), since the diameter of the opening 25 a is smaller under condition F than under condition E, the film thickness in the central portion of the substrate is smaller. Also, when the substrate W is plated in a plating solution having a comparatively low electrical resistance with the diameter of the opening 25 a set to 220 mm and with the diameter of the opening 60 a set to 274 mm (hereinafter this condition will be referred to as condition D), since the diameter of the opening 60 a is smaller under condition D than under condition F, the film thicknesses on the periphery of the substrate is smaller.

As shown in FIG. 25, even if the substrates W are plated in a plating solution having a comparatively low electrical resistance, if the diameter of the opening 25 a is set smaller than the diameter (260 mm: conditions B and C) of the opening 25 a suitable for plating of the substrates W in a plating solution having a comparatively high electrical resistance, it is possible to curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see conditions D and F). Furthermore, by adjusting the diameter of the opening 60 a in the regulation plate 60, the film thickness on the periphery of the substrate W can be adjusted, making it possible to further curb the reduction in the in-plane uniformity of film thickness on the substrates W due to the terminal effect (see condition D).

As shown in FIGS. 23 to 25, in order to perform plating with good uniformity under conditions differing in the influence of the terminal effect, desirably the diameter of the opening 25 a in the anode mask 25 has a wide variation range than the diameter of the opening 60 a in the regulation plate 60. In order to make the diameter of the opening 25 a in the anode mask 25 adjustable in a wide variation range, a mechanism which uses the aperture blades 27 described above is suitable. Since the anode mask 25 and substrate W are spaced away from each other, even if the opening 25 a in the anode mask 25 is decreased, an electric flux spreads between the anode mask 25 and substrate W, allowing the film thickness distribution of the plating film to be adjusted in a wide range of the substrate W.

Even if the influence of the terminal effect is excluded, the plating film tends to become thick on the periphery of the substrate W because the electric flux spreading outward between the anode mask 25 and substrate W concentrates on the periphery of the substrate W. Adjustment of plating film thickness in a comparatively narrow region on the periphery of the substrate W such as described above is achieved by the opening adjustment portion 63 of the regulation plate 60. The regulation plate 60, which is located close to the substrate W, can directly shield electric fields on the peripheral portion of the substrate W and adjust the plating film thickness even by a comparatively small change in an aperture diameter.

An embodiment of the present invention has been described above, but the embodiment described above is intended to facilitate understanding of the present invention and is not meant to limit the present invention. The present invention can be modified and improved without departing from the spirit and scope of the present invention. Needless to say, the present invention includes equivalents thereof. Also, the components described in the appended claims and in the specification may be used in any combination or any of the components may be omitted as long as at least some of the problems described above can be solved or as long as at least some of the advantageous effects described above can be achieved. For example, in the embodiments described above, the plural aperture blades 27 are used as a mechanism for adjusting the diameter of the opening 25 a in the anode mask 25, and the plural first blades 71A and plural second blades 71B are used as a mechanism for adjusting the diameter of the opening 60 a in the regulation plate 60. However, the diameter of the opening 25 a in the anode mask 25 may be adjusted using the plural first blades 71A and plural second blades 71B and the opening 60 a in the regulation plate 60 may be adjusted using the plural aperture blades 27. Also, not only the plural aperture blades 27 and the plural first blades 71A and plural second blades 71B, but also an adjustment mechanism of another form may be adopted.

REFERENCE SIGNS LIST

-   10 Plating apparatus -   20 Anode holder -   21 Anode -   25 Anode mask -   25 a Opening -   40 Substrate holder -   60 Regulation plate -   60 a Opening -   71, 71A First blade -   71B Second blade -   72, 72A, 72B Slide pin -   73 Guide pin -   80, 80A, 80B Ring member -   81, 81A, 81B Slide slot -   90, 90A, 90B Blade presser member -   91 Guide slot -   W Substrate 

1. A regulation plate used to adjust an electric current between an anode and a substrate to be plated, comprising: a plate main body provided with a rim forming a first opening adapted to allow passage of an electric current; plural first blades used to narrow a diameter of the first opening; and a first moving mechanism adapted to translate the plural first blades in a radial direction of the first opening.
 2. The regulation plate according to claim 1, wherein: the first moving mechanism includes a ring member placed along the rim; either of the ring member and the plural first blades includes a slide slot inclined in the radial direction of the first opening; and another of the ring member and the plural first blades includes a slide pin adapted to slide along the slide slot.
 3. The regulation plate according to claim 2, wherein: the first moving mechanism includes a blade presser member fixed on a side opposite the ring member of the plural first blades; either of the blade presser member and the plural first blades includes a guide slot formed in parallel to a translation direction of the first blades; and another of the blade presser member and the plural first blades includes a guide pin adapted to slide along the guide slot.
 4. The regulation plate according to claim 2, wherein: the first moving mechanism includes a rotating member used to rotate the ring member in a circumferential direction; and the rotating member includes a ring portion fixed to the ring member, and a lever portion adapted to rotate the ring portion in the circumferential direction.
 5. The regulation plate according to claim 4, wherein: either of the plate main body and the ring member includes a support slot formed along a rotation direction of the ring member; and another of the plate main body and the ring member includes a support pin slidably engaged with the support slot.
 6. The regulation plate according to claim 1, wherein an inner peripheral edge of each of the plural first blades is formed into an arc shape and is overlapped with other first blades, forming a substantially circular inner peripheral edge.
 7. The regulation plate according to claim 1, further comprising: plural second blades placed at a position shifted from the plural first blades in a direction orthogonal to the radial direction of the first opening and used to narrow the diameter of the first opening; and a second moving mechanism adapted to translate the plural second blades in the radial direction of the first opening.
 8. The regulation plate according to claim 7, wherein the plural first blades and the plural second blades are arranged such that a straight line joining a center of an opening formed by the first blades and a center of an opening formed by the second blades is orthogonal to the radial direction of the openings.
 9. A regulation plate used to adjust an electric current between an anode and a substrate to be plated, comprising: a first plate main body provided with a first rim forming a first opening adapted to allow passage of an electric current and plural first blades used to narrow a diameter of the first opening; and a second plate main body provided with a second rim forming a second opening adapted to allow passage of an electric current and plural second blades used to narrow a diameter of the second opening, wherein the first plate main body and the second plate main body are coupled together such that a straight line joining a center of an opening formed by the plural first blades and a center of an opening formed by the plural second blades is orthogonal to the radial direction of the openings.
 10. The regulation plate according to claim 7, wherein the diameter of the opening formed by the plural first blades and the diameter of the opening formed by the plural second blades are configured to be adjustable independently of each other.
 11. A plating apparatus comprises: an anode holder configured to hold an anode; a substrate holder placed opposite the anode holder and configured to hold a substrate; an anode mask mounted integrally on the anode holder and provided with a second opening adapted to allow passage of an electric current flowing between the anode and the substrate; and the regulation plates according to claim 1, wherein the anode mask includes an adjustment mechanism adapted to adjust a diameter of the second opening.
 12. A plating method comprising: placing an anode holder in a plating bath, where the anode holder is integrally provided with an anode mask having a first opening adapted to allow passage of an electric current flowing between an anode and a substrate; placing a substrate holder adapted to hold a first substrate in the plating bath; placing a regulation plate between the anode mask and the substrate, where the regulation plate includes a second opening and third opening adapted to allow passage of the electric current flowing between the anode and the substrate; plating the first substrate by adjusting a diameter of the first opening to a first diameter; placing a substrate holder adapted to hold a second substrate in the plating bath; and plating the second substrate by adjusting a diameter of the first opening to a second diameter smaller than the first diameter and by changing the diameters of the second opening and third opening in the regulation plate. 